Prior art still image and movie cameras memorialized image data on media (e.g., film or magnetic tape), but did not include provision to store other useful information.
Some years ago, still-image cameras with the capability to insert visible date text in a corner of the image frame became available, solving the problem of trying to recall the dates that photos of interest were taken.
More recently, the Advanced Photo System provided a magnetic encoding medium on the back of photographic film, permitting additional information to be stored (e.g., exposure information, whether flash was used, desired print size, etc.).
With the growing popularity of digital storage of multimedia data, it would be helpful if auxiliary data could be stored in association with the multimedia data. Such storage is now possible in the header fields of certain popular data formats, but such data can be lost if the file is converted to another format.
In one embodiment of the invention, auxiliary data about a media signal is steganographically encoded (“watermarked”) within the media signal itself. By integrating the media signal and the associated data in this fashion, the auxiliary data cannot become separated from the media signal. A great number of useful systems are thereby reliably enabled.
In another embodiment, a reference to auxiliary data is steganographically encoded within the media signal. The auxiliary data is stored in a metadata database that maps the reference encoded in the media signal to its corresponding metadata. Various application programs and devices can access the metadata by extracting the reference from the media signal, and querying the database for metadata corresponding to the reference. The metadata database may be implemented in a network server to make metadata readily available to devices and applications distributed throughout a computer network.
The steganographic link may be used to retrieve metadata across media management systems. In one configuration, for example, media management systems have metadata servers that maintain metadata for a collection of media signals. The metadata server is responsible for responding to requests for metadata associated with media titles in its collection. In the event that a metadata server does not have metadata associated with a particular media title, it forwards the reference extracted from the media signal to a metadata router, which in turn, re-directs the request to the appropriate metadata server.
The steganographic data may be embedded in a media signal within a media signal capture device, or elsewhere. In one embodiment, the steganographic data is embedded in the media signal as part of the process of uploading it to a network. In another embodiment, a capture device embeds steganographic data in the media signal before uploading it to an external device.
The foregoing and additional features and advantages will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.